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Background: Most patients with hepatitis B virus (HBV) infection will develop hepatocellular carcinoma (HCC). This study aimed to explore the potential mechanism of miR-142-3p in HCC caused by HBV infection.Methods: HepG2 cells and M1 macrophages were cocultured and then infected with HBV to establish an in vitro model. MicroRNA (miRNA) and messenger RNA (mRNA) expression was analyzed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot. The protein expressions of COX2, ACSL4, PTGS2, GPX4, and NOX1 were analyzed by Western blot. Flow cytometry and TUNEL assays were used to assess cell reactive oxygen species (ROS) and ferroptosis, respectively. Cell invasion and migration were measured by Transwell assay. To evaluate the ferroptosis of M1-type macrophages, glutathione (GSH), malondialdehyde (MDA), and Fe 2+ content was detected by corresponding kits. Dual luciferase reporter gene detection verified the targeting relationship between miR-142-3p and SLC3A2.Results: MiR-142-3p was highly expressed in HBV-infected HCC patients and HBV-infected M1-type macrophages. Inhibition of miR-142-3p or overexpression of SLC3A2 reversed ferroptosis and inhibited the proliferation, migration, and invasion of HCC cells.Conclusions: Our findings indicated that miR-142-3p promoted HBV-infected M1-type macrophage ferroptosis through SLC3A2, affecting the production of GSH, MDA, and Fe 2+ and accelerating the development of HCC. The regulation of miR-142-3p and its target genes will help to clarify the pathogenesis of HCC induced by HBV infection and provide new theoretical foundations and therapeutic targets.

Background Hepatocellular carcinoma (HCC) cell-derived exosomes have shown effects on inducing M2 macrophage polarization and promoting HCC progression. MiR-452-5p was reported by recent studies to promote malignancy progression as an exosomal microRNA that secreted by HCC cells, of which the underlying mechanism remains unclear. Here, we further explored how miR-452-5p functions in HCC. Methods MiR-452-5p expressions in HCC cells was examined by in situ hybridization. Next, HCC cell lines were transfected with the mimics or the inhibitor of miR-452-5p. Transfected cells' biological behavior were analyzed by CCK-8, flow cytometry, and Transwell assay. Then, exosomes were purified from miR-452-5p inhibited or overexpressed HCC cells and cocultured with macrophages to examine the role of miR-452-5p in macrophage polarization. To examine the role of exosomal miR-452-5p on macrophage polarization and tumor growth. We also performed the dual-luciferase assay to explore the targeting relationship between miR-452-5p and TIMP3. Results The upregulation of miR-452-5p was identified in HCC. The effects of HCC cell-derived exosomes on accelerating HCC migration and invasion and inducing M2 macrophage polarization were confirmed, which were further enhanced after overexpressing miR-452-5p but neutralized after silencing miR-452-5p. In addition, in vivo experiments demonstrated the effect of miR-452-5p on accelerating HCC growth and metastasis. Also, we identified that TIMP3 overexpression inhibited the promoted cell invasion and migration by HCC cell-derived exosomes. Conclusion Exosomal miR-452-5p secreted from HCC cells could induce polarization of M2 macrophage and therefore stimulating HCC progression by targeting TIMP3. Thus, miR-452-5p might be a potential biomarker for HCC prognosis.

Background Exosomes are becoming an important mediator of the interaction between tumor cells and the microenvironment. Ferroptosis is a newly discovered type of cell death. However, its role in the progression of liver cancer is largely unknown. The aim of the presents study was to analyze the mechanism by which hepatitis B virus (HBV)-positive liver cancer secretes exosomes to mediate the iron death of M1 macrophages, thereby promoting the development of liver cancer. Methods Liver cancer tissues and peripheral blood with positive and negative clinical HBV infection were collected, and M-type macrophages, miR-142-3p, and recombinant solute carrier family 3, member 2 ( SLC3A2 ) expressions were detected in the samples. CD80 + M1 macrophages and CD163 + M2 macrophages were isolated from the 2 tissues, and levels of miR-142-3p, SLC3A2 , and ferroptosis markers were detected. Exosomes of HBV-positive hepatocellular carcinoma (HCC) cells were isolated and co-cultured with M1 macrophages to observe their effect on the invasion ability of HCC cells. Results The expression of miR-142-3p significantly increased in the exosomes extracted from the peripheral blood of patients with HBV-positive liver cancer. Genes related to intracellular iron metabolism and homeostasis, such as ferritin heavy chain 1 (FTH1), transferrin receptor 1 (TfR1), recombinant glutathione peroxidase 4 (GPX4), and activating transcription factor 4 (ATF4), had abnormal expression levels in M1 macrophages. HBV-positive HCC exosomes treated with M1-type macrophages had a weakened inhibitory effect on the invasion of HCC cells, but ferroptosis inhibitors could reverse the effect of HBV-positive HCC exosomes treated M1-type macrophages on HCC cells. Knockdown of the expression of miR-142-3p can also weaken the invasive ability of liver cancer cells. Conclusions The results of the present study confirmed that HBV-positive liver cancer cell exosomal miR-142-3p can promote the progression of liver cancer by inducing iron death of M1-type macrophages.